INTRODUCTION
Lower urinary tract symptoms (LUTS) are highly prevalent among aging men and significantly impact their quality of life (QoL) [1, 2]. While traditionally attributed to bladder outlet obstruction (BOO) secondary to benign prostatic hyperplasia (BPH), emerging evidence suggests a multifactorial etiology involving both prostate-related and bladder-specific dysfunctions. Among these, storage symptoms—including urgency, frequency, and nocturia—are particularly distressing and frequent in overactive bladder (OAB) syndrome [3-6]. Storage symptoms arise during the bladder filling phase due to heightened afferent activity, particularly from in-series tension receptors sensitive to increases in prostate volume and detrusor contraction [7]. Notably, detrusor overactivity (DO) is observed in 61% of male patients with LUTS attributed to BPH, with no clear correlation to BOO severity [8]. However, the higher prevalence of DO in patients with BOO suggests that underlying bladder dysfunction plays a key role in LUTS pathophysiology [9].
Surgical indications for these patients align with those for BOO rather than being tailored specifically for OAB [10, 11]. While BOO-induced DO may contribute to symptomatology, the degree to which surgical relief translates into storage symptom resolution varies. Previous studies have reported inconsistent outcomes regarding postoperative OAB symptom improvement, the need for adjunctive anticholinergic therapy, and urodynamic changes [12].
This systematic review and meta-analysis aims to evaluate the outcome of surgery, in men with BPH associated with preoperative OAB syndrome vs those without OAB syndrome.
MATERIALS AND METHODS
Aim of the Review
The main outcome of this study was to assess differences in the severity of postoperative LUTS following surgical procedure for clinical BPH comparing men with preoperative (predominantly) nonneurogenic OAB symptoms (namely storage phase symptoms)/DO diagnosed at flow/pressure study (including the old definition of “bladder instability”) versus men without preoperative predominantly voiding phase symptoms/absence of DO diagnosed at flow/pressure study. The secondary outcomes were the difference in the rate of postoperative urge incontinence, need for postoperative anticholinergics, difference in postoperative QoL and voiding parameters, including maximum urinary flow rate (Qmax) and postvoid residual volume (PVR).
Literature Search
This study adhered to the 2020 Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) framework. A comprehensive literature search was performed on 12th May 2025, using Cochrane Central Register of Controlled Trials, PubMed, Embase and Scopus. MeSH (medical subject heading) terms and keywords were used as follows: (urodynamics OR overactive OR overactivity) AND (bladder OR detrusor) AND (benign prostatic hyperplasia OR BPH OR bladder outlet obstruction) AND (transurethral surgery OR TURP OR enucleation OR vaporization). There was no date restriction. This review was registered in PROSPERO (receipt # 638489).
Selection Criteria
The PICOS (Patient Intervention Comparison Outcome Study type) model was used to frame and answer the clinical question. Population: men who underwent a surgical procedure for clinical BPH with preoperative nonneurogenic OAB symptoms (namely storage phase symptoms)/DO diagnosed at flow/pressure study; Intervention: any surgical procedure; Comparison: men without preoperative predominantly voiding phase symptoms/absence of DO diagnosed at flow/pressure study; Outcomes: primary: Differences in total International Prostate Symptom Score (T-IPSS) and its storage symptom subscore (SS-IPSS); secondary: Differences in postoperative QoL item of IPSS, incidence of postoperative urge urinary incontinence, need for postoperative anticholinergics, and postoperative Qmax and PVR; Study type: retrospective and prospective studies. The assessment of outcomes was categorized according to the time between the operation and follow-up (i.e., 1, 3, 6, and 12 months).
Study Screening and Selection
Two distinct authors screened all gathered records through Covidence Systematic Review Management. A third author solved discrepancies. Studies were accepted and included based on PICOS eligibility criteria. Studies with no data on preoperative symptoms and/or urodynamics or with no postoperative data available for meta-analysis were excluded. Reviews, meeting abstracts, letters to the editor, case reports, non-English articles and editorials were also excluded. The full text of the screened papers was selected if deemed relevant to the aim of this study. The reference list of full-text screened papers was also analyzed for further studies.
Statistical Analysis
Categorical variables were assessed using the Cochran-Mantel-Haenszel Method with the random effect model and reported as odds ratio (OR), 95% confidence interval (CI), and P-values. Analyses were 2-tailed and the significance was set at P<0.05 and a 95% CI. Continuous variables were pooled using the inverse variance of the mean difference with a random effect, 95% CI, and P-values. A subanalysis was conducted to investigate potential differences in the outcomes according to the surgical procedure. Study heterogeneity was assessed utilizing the I2 value. Substantial heterogeneity was defined as an I2 value >50%. Meta-analysis was conducted using Review Manager (RevMan) 5.4 software by Cochrane Collaboration. The quality assessment of the included studies was performed using the methodological index for nonrandomized studies (MINORS) instrument [13], an instrument built to evaluate the methodological quality of nonrandomized surgical studies. It has 12 items with each score ranging from 0 to 2 (the higher the score, the better the quality of the study).
RESULTS
Literature Screening
The initial literature search generated 1,615 papers. One paper was found among reference lists. After removing 488 duplicated papers, 1,128 studies remained for screening. Another 1,084 papers were further excluded after the title and abstract screening due to their lack of relevance. The full texts of the remaining 44 studies were assessed and 31 papers were further excluded. Finally, 13 papers were accepted and included in the review [14-26]. Fig. 1 shows the 2020 PRISMA flow diagram.
Study Characteristics
The 13 eligible studies included a total of 1,436 patients (Table 1). There were 632 patients in the OAB group and 804 patients in the No OAB group. There were 3 prospective nonrandomized studies [17, 22, 25] and the remaining ones were retrospective [14-16, 18-21, 23, 24, 26]. Five studies used TURP as surgical modality [14, 15, 17, 18, 20], 3 studies used holmium laser enucleation of the prostate [21, 23, 25], 1 study adopted holmium laser incision of the prostate [24], and the remaining ones employed laser vaporization of the prostate [16, 19, 22].
Study Quality Assessment
Table 2 shows the details of quality assessment of the included studies. The highest MINORS score was 21, whilst the lowest score was 13.
Primary Outcomes
Total-IPSS
Data at 1-month follow-up were not available for a meta-analysis.
Three-month postoperative total-IPSS: Meta-analysis from 6 studies (256 cases in the OAB group and 298 cases in the No OAB group) shows that the T-IPSS is comparable between the groups (MD, 0.39; 95% CI, -1.21 to 1.99; P=0.63). Study heterogeneity is moderate (I2=64%) (Fig. 2A). Subgroup analysis confirms this finding.
Changes in total-IPSS after 3 months: Meta-analysis from 4 studies (139 cases in the OAB group and 176 cases in the No OAB group) shows that there was no difference between the groups (MD, 0.63; 95% CI, -0.87 to 2.13; P=0.41). Study heterogeneity is low (I2=37%) (Fig. 2B). However, subgroup analysis shows that there was a significantly difference in the TURP group favoring the No OAB group (MD, 2.30; 95% CI, 0.18–4.42; P=0.03).
Six-month postoperative total-IPSS: Meta-analysis from 5 studies (311 cases in the OAB group and 337 cases in the No OAB group) shows that there was no difference between the groups (MD, 1.11; 95% CI, -1.18 to 3.40; P=0.34) (Fig. 3A). Study heterogeneity is substantial (I2=83%) (Fig. 3A). Subgroup analysis confirms this finding.
Changes in total-IPSS after 6 months: Meta-analysis from 4 studies (239 cases in the OAB group and 353 cases in the No OAB group) shows that there was no difference between the groups (MD, -0.46; 95% CI, -2.79 to 1.87; P=0.70) Study heterogeneity is high (I2=75%) (Fig. 3B). However, subgroup analysis shows that there was a significantly difference in the PVP group favoring the OAB group (MD, -4.40; 95% CI, -8.18 to -0.62; P=0.02).
Twelve-month postoperative total-IPSS: Meta-analysis from 2 studies (91 cases in the OAB group and 138 cases in the No OAB group) shows that the 12-month postoperative T-IPSS favors the No OAB group (MD, 3.66; 95% CI, 1.87–5.45; P<0.0001). Study heterogeneity is not relevant (I2=0%) (Fig. 4). Subgroup analysis confirms this finding.
Storage symptoms-IPSS
Data at 1-, 3-, and 12-months follow-up were not available for meta-analysis.
Postoperative storage symptoms-IPSS: Meta-analysis from 2 studies (125 cases in the OAB group and 178 cases in the No OAB group) shows that the 6-month postoperative SS-IPSS favors the OAB group (MD, 1.06; 95% CI, 0.18 to 1.95; P=0.02) Study heterogeneity is not significant (I2=0%) (Fig. 5A). Subgroup analysis shows that the difference was related to the holmium laser enucleation of the prostate (HoLEP) group (MD, 1.20; 95% CI, 0.07 to 2.33; P=0.04).
Changes in storage symptoms-IPSS: Data at 3- and 6-month follow-up were not available for meta-analysis. Meta-analysis from 2 studies (85 cases in the OAB group and 134 cases in the No OAB group) shows that there was no difference in change of SS-IPSS after 3 months between the groups (MD, -0.72; 95% CI, -1.72 to 0.27; P=0.16) Study heterogeneity is not significant (I2=0%) (Fig. 5B). Subgroup analysis confirmed this finding.
Meta-analysis from 3 studies (137 cases in the OAB group and 259 cases in the No OAB group) shows no difference in change of SS-IPSS after 6 months (MD -0.45; 95% CI -1.25 to 0.35; P=0.27). Study heterogeneity is considerable (I2=77%) (Fig. 5C). Subgroup analysis confirms this finding.
Secondary Outcomes
Quality of life
Data at 1- and 12-month follow-up were not available for a meta-analysis.
Three-month QoL: Meta-analysis from 4 studies (176 cases in the OAB group and 241 cases in the No OAB group) shows that there was no difference between the groups (MD, 0.15; 95% CI, -0.18 to 0.48; P=0.38). Study heterogeneity is low (I2=39%) (Fig. 6A). Subgroup analysis confirms this finding.
Six-month QoL: Meta-analysis from 2 studies (181 cases in the OAB group and 220 cases in the No OAB group) shows that the 6-Month QoLI after HoLEP favors the OAB group (MD -0.36, 95% CI -0.62 to -0.10, P=0.006). Study heterogeneity is not relevant (I2=0%) (Fig. 6B).
Changes in QoL after 6 months
Meta-analysis from 2 studies (79 cases in the OAB group and 207 cases in the No OAB group) shows that the changes in QoL after 6 months significantly favors the No OAB group (MD, -0.61; 95% CI, -1.18 to -0.05; P=0.03). Study heterogeneity is moderate (I2=50%) (Fig. 6C). Subgroup analysis confirms this finding.
Six-month incidence of urge urinary incontinence
Meta-analysis from 2 studies (91 cases in the OAB group and 129 cases in the No OAB group) shows no difference between the groups (OR, 2.42; 95% CI, 0.97–6.01; P=0.06). Study heterogeneity is low (I2=9%) (Fig. 7A). However, subgroup analysis shows that there is a significant difference in the TURP group favoring the No OAB group (OR, 3.92; 95% CI, 1.12 to 13.77; P=0.03).
Need for postoperative anticholinergic therapy
Meta-analysis from 2 studies (94 cases in OAB group and 77 cases in the No OAB group) shows that the need for postoperative anticholinergic therapy favors the No OAB group (OR, 2.47; 95% CI, 1.01–6.04; P=0.05). Study heterogeneity is not relevant (I2=0%) (Fig. 7B). Subgroup analysis shows that this result is related to the HoLEP group (OR, 1.60; 95% CI, 1.01–6.04; P=0.05).
Maximum urinary flow rate
Data at 1-month follow-up were not available for meta-analysis.
Three-month maximum urinary flow rate: Meta-analysis from 5 studies (193 cases in the OAB group and 230 cases in the No OAB group) shows no difference between the groups (MD, -0.85 mL/sec; 95% CI, -3.20 to 1.50; P=0.48) Study heterogeneity is moderate (I2=46%) (Fig. 8A). However, subgroup analysis shows that there was a significantly difference in the HoTUIP (holmium laser transurethral incision of the prostate) group favoring the OAB group (MD, -8.40 mL/sec; 95% CI, -15.67 to -1.13; P=0.02).
Six-month maximum urinary flow rate: Meta-analysis from 4 studies (275 cases in the OAB group and 297 cases in the No OAB group) shows that the 6-month postoperative Qmax favors the No OAB group (MD, 1.47 mL/sec; 95% CI, 0.80–2.13; P<0.0001). Study heterogeneity is not relevant (I2=0%) (Fig. 8B). Subgroup analysis shows that this result was related to the HoLEP group favoring the No OAB group (MD, 1.48 mL/sec; 95% CI, 0.81–2.15; P<0.0001).
Twelve-month maximum urinary flow rate: Meta-analysis from 2 studies (91 cases in the OAB group and 138 cases in the No OAB group) shows no difference between the groups (MD, -0.74 mL/sec; 95% CI, -2.64 to 1.16; P=0.45). Study heterogeneity is low (I2=11%) (Fig. 8C). Subgroup analysis confirms this finding.
Postvoiding residual urine
Data at 1- and 12-month follow-up were not available for meta-analysis.
Three-month postvoiding residual urine: Meta-analysis from 4 studies (132 cases in the OAB group and 101 cases in the No OAB group) shows no difference between the groups (MD, -3.18 mL; 95% CI, -35.28 to 28.91; P=0.85). Study heterogeneity is high (I2=79%) (Fig. 9A). Subgroup analysis confirms this finding.
Six-month postvoiding residual urine: Meta-analysis from 4 studies (275 cases in the OAB group and 288 cases in the No OAB) shows no difference between the groups (MD, -3.35 mL; 95% CI, -8.49 to 1.78; P=0.20). Study heterogeneity is not relevant (I2=0%) (Fig. 9B). Subgroup analysis confirms this finding.
DISCUSSION
Storage symptoms significantly affect QoL, with OAB present in 20%–40% of patients undergoing BPH surgery [27, 28]. TURP is well known to improve both voiding and storage symptoms, albeit to different extents (82.6%–87% vs. 60%–80%, respectively) [29]. However, limited research has focused on the role of preoperative storage phase symptoms in predicting outcomes post-surgery, and the available findings are often contradictory.
Seki et al. [30] analyzed a cohort of 384 TURP patients with BOO, identifying preoperative OAB as a negative predictor of symptom relief following surgery. Conversely, a single-center study found that while BOO was not a definitive predictor of surgical success, DO played a crucial role in determining outcomes [14]. The primary causes of DO included BOO, denervation supersensitivity, neuroplasticity (age-related), and myogenic dysfunction. The study highlighted that patients with OAB secondary to BOO experienced substantial improvement after surgery, whereas those with OAB due to other etiologies often continued to report bothersome storage symptoms postoperatively. These findings underscore the necessity of thoroughly assessing OAB before surgery to counsel patients for postoperative persistence of the same.
Zhao et al. [20] evaluated 128 patients with OAB associated with BOO who underwent TURP, stratifying patients into 3 groups based on OAB severity. Postoperative parameters showed no significant differences across groups in terms of symptom relief, functional outcomes, or QoL. However, symptom resolution was most pronounced in the “mild OAB” group compared to the “moderate” and “severe” groups, although all categories experienced some degree of improvement. These findings were corroborated by Masumori et al. [18], who demonstrated sustained symptom relief at a 5-year follow-up. Similarly, Kwon et al. [31] observed a reduction in OAB prevalence from 44.9% at baseline to 36.1% at 6-month post-HoLEP.
Given the potential persistence of OAB symptoms following BPH surgery, clinicians should carefully evaluate OAB in all patients considered for surgical intervention. OAB symptoms may not only persist but could also be exacerbated in the early postoperative months, compromising surgical outcomes and the patient’s QoL, at least in the early postoperative phase [32].
Our finding demonstrates that patients with preoperative OAB symptoms or DO exhibited modest improvements in SSIPSS at 6 months postoperatively compared to those without OAB symptoms. This improvement was particularly evident in patients undergoing HoLEP. These findings align with previous research suggesting that BOO is a key factor in OAB pathogenesis in patients with BPH [33]. However, the lack of significant SS-IPSS changes at 6 months suggests a gradual resolution of storage symptoms, potentially influenced by the extent of preoperative detrusor dysfunction. This observation is consistent with the considerable variability in OAB symptom resolution postoperatively [34].
In our analysis, T-IPSS does not significantly differ between groups at 3 and 6 months, except in the PVP group, where patients with OAB experienced greater improvements at 6 months. Notably, at 12 months, patients with preoperative OAB symptoms had significantly higher T-IPSS, indicating a potentially less pronounced long-term improvement. Differences in patient characteristics and surgical techniques may contribute to these discrepancies, as Ahyai et al. [35] reported sustained TIPSS improvements up to 12 months, irrespective of preoperative OAB status.
QoL outcomes demonstrated discordant results. At 3 months, no significant differences were observed, while at 6 months, QoL significantly improved in patients with OAB undergoing HoLEP, suggesting that patients with preoperative OAB symptoms may experience greater QoL benefits over time. The improvement in QoL at 6 months within this group implies that alleviation of storage symptoms may be a key driver of enhanced patient-reported outcomes. Nonetheless, variability across different surgical techniques may stem from discrepancies between patient expectations and actual surgical results.
Our meta-analysis also shows no significant difference in UUI incidence between the groups but UUI is higher in patients undergoing TURP compared to controls. This finding could be attributed to persistent DO or residual bladder dysfunction despite BOO relief.
The need for postoperative anticholinergic therapy is significantly higher in patients with preoperative OAB symptoms, particularly after HoLEP. This suggests that, while surgical intervention reduces overall symptoms, some patients continue to report persistent OAB symptoms after surgery and require pharmacological management and the rate is reported up to 30% of patients with preoperative OAB symptoms [36]. The persistence of OAB symptoms after surgery might be related in some patients to irreversible bladder dysfunction from longstanding obstruction [37].
Regarding voiding parameters, we found that at the 3-month follow-up, there is no significant difference in Qmax but a 6-month Qmax significantly favors the No OAB group, with a particularly pronounced effect in patients who underwent HoLEP even if this difference is not clinically meaningful. In fact, at the 12-month follow-up, data from 2 studies confirm no significant difference in Qmax between the groups, indicating that initial disparities in postoperative Qmax may diminish over time, ultimately leading to comparable long-term outcomes.
Regarding PVR, analysis of 3- and 6-month postoperative data reveals no significant difference. This is in line with prior research suggesting that PVR may be greatly influenced by detrusor contractility [38, 39].
This meta-analysis has several limitations. First, substantial heterogeneity exists among the included studies, which may have contributed to the observed variability in OAB symptom improvement, particularly at the six-month follow-up. Second, the lack of randomized controlled trials introduces risks of selection bias and confounding variables, which may have influenced the pooled estimates. While HoLEP appears to yield more favorable outcomes than TUIP or vaporization, its superiority over TURP could not be definitively established. Additionally, inconsistencies in the reporting of TURP techniques and energy modalities hindered a more detailed comparative analysis. Moreover, the variation in follow-up durations across studies may have affected the assessment of long-term outcomes. While OAB symptoms may improve over time, these findings highlight the need for extended follow-up periods to determine whether symptom relief is sustained beyond 6 months. In conclusion, this meta-analysis demonstrates that while BPH patients with preoperative OAB experienced comparable overall postoperative LUTS improvements, they exhibited persistently higher storage symptoms. Notably, QoL improvement was more pronounced among OAB patients during follow-up highlighting that storage symptoms play a pivotal role in patients’ QoL. Qmax was initially superior in the non-OAB group but showed convergence over time, while PVR remained comparable between groups. However, the available evidence shows inconsistent and procedure-dependent differences in storage symptoms, QoL trajectories, and selected functional parameters. Similarly, although some analyses suggest a greater need for postoperative anticholinergic therapy in the OAB group, the restricted number of studies precludes firm conclusions.
These findings support careful preoperative counseling regarding the potential persistence of storage symptoms but does not allow definitive prognostication regarding long-term functional outcomes. High-quality prospective studies with standardized assessments are required to clarify the true impact of preoperative OAB on postoperative results and to better guide clinical decision-making.
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